Insertable elastic strip



NOV. 21, 1967 M M MADSON INSERTABLE ELASTI-C `STRIP Filed Oct. 28,

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United States Patent Gice 3,353,245 Patented Nov. 2l, 1967 IllinoisFiled Uct. 28, 1963, Ser. No. 319,359 4 Claims. (Cl. 29-129.5)

This invention relates to elastic material which is adapted to beinserted into and retained by a machine operating member and itparticularly relates to an insertable elastic strip adapted to be usedwith various operating elements, such as feed rolls or pull rolls forvarious materials, such as paper or corrugated cardboard, and also inscoring operations on corrugated cardboard.

In industry, there are many applications wherein elastomeric materialsare bonded or connected in some manner to operating members, such asmetallic sleeves or rollers. Common use of such devices is found in thepaper and cardboard box industries wherein rubber or plastic materialsare molded directly on or cemented to metallic rolls used for feeding orpulling cardboard or paper during various stages of their processing.

However, it is common, particularly in the case of rubber, to have theelastic material deteriorate or become damaged, whereby a portion of orall of the elastic material must be replaced. Often, this means severalhours of down vtime for a particular machine or even for an entireproduction line. This results from the fact that the entire feed roll orpull roll must be disassembled from the machine and another feed or pullroll must be placed on the machine. The removed roll or operating membermust then be sent back to the manufacturer and the damaged ordeteriorated elastic material must be replaced. Sometimes, if a spareroller is not avaliable, several days of down time may result before therepaired roller is returned. Thus, it would clearly be highlyadvantageous if elastic material on a machine operating element could bereplaced either partially or entirely, without dismantling the entiremachine and replacing the operating element.

Furthermore, not only is it important that the elastic material bereadily replaceable, but it is also of great importance that the elasticmaterial be adaptable to be firmly and securely maintained in place onthe operating member. Thus, even if the elastic material is replaceableon the operating member without dismantling the entire machine, there isthe added problem of 'attaining an appropriate bond. Although thematerial could conceivably be cemented to the machine, it is often quitedifficult to obtain a rm and lasting bond between the elastic materialand a metallic surface, particularly with unskilled personnel; also,cements and adhesives are often dicult to handle and apply. Therefore,it would clearly be highly desirable if the elastic materia-l could bebonded or connected to an operating element of the machine without thenecessity of using glue or cement.

It is therefore an important object of this inevntion to provide elasticor elastomeric material adaptable to be inserted and rmly maintained inplace on an operating element.

It is a further important object of this invention to provide aninsertable elastic strip of material which may be retained in place on amachine operating element without the use of cement or glues.

It is also an object of this invention to provide a strip of elastomericmaterial which may be easily and readily inserted in or removed from agroove provided in a cooperating operating element, while at the sametime avoiding the necessity of using adhesive means for rmly retainingthe strip in place on the operating element.

It is an additional object of this invention to provide an elongatedstrip of elastic material adaptable to be connected to an associatedoperating member, wherein the strip is provider with a retaining portionwhich is insertable into place on a groove provided in the operatingmember.

It is still another object of this invention to provide a strip ofelastic material adaptable to be retained in a groove provided in anassociated machine operating member, wherein the retaining portion is ofless cross-sectional area than the cross-sectional area of the groove soas to provide for easy insertion of the retaining portion in the grooveand also -so as to provide for frictional retention of the strip withinthe groove upon application of pressure to the strip.

Further purposes and objects of this invention will appear as thespecification proceeds.

A particular embodiment of the present invention is illustrated in theaccompanying drawings wherein:

FIGURE l is an end elevational view of elastic material in place on amachine roller member;

FIGURE 2 is a sectional view taken along the line 2--2 of FIGURE 1;

FIGURE 3 is a fragmentary sectional view, similar to FIGURE 2, shownduring scoring operations on corrugated cardboard; and

FIGURE 4 is a fragmentary, insertable elastic strip.

Referring to the drawings, an operating head or roller 10 lof a machine(not shown) is illustrated in association with an elongated elasticstrip 12. Although, the operating member 10 is shown as a roller, it isto be understood that'the elastic strip may be used in connection withother types of machine members, such as ila-t members, for example,platens. The cylindrical head 10 shown in the drawings is formed by apair of semi-circular halves 14 which are securely joined together bymeans of bolts 16, which pass into the threaded openings 18 in one ofthe halves 14.

A continuous dovetail groove 22 is provided in the cylindrical surface20 of the rollers 10 and 17 and passes circumferentially around the head10. The groove 22 includes a constricted or relatively narrow opening orinlet 24. The opening 24 meets the diverging or downwardly and outwardlyinclined walls 26; the walls 26 terminate at the bottom or base 28 ofthe groove 22, the bottom being substantially parallel to the opening24. Although the groove would conventionally extend completely aroundthe roller 10, it may pass only partially therearound.

The elastic strip 12 includes an operating or Working portion 30 and aretaining portion 32. The operating portion 30 meets the retainingportion 32 along the lower surface 34 of the operating portion 12, thelower surface 34 being in contact with parallel strips of thecylindrical surface 20. Generally, the operating portion 30 isrectangular in cross-section, sides 36 connecting the lower surface 34to the upper surface 34, which may be contoured to any desired shape.The retaining portion 32 includes a pair of diverging legs 38, formed bya V-shaped groove 40 in the base or bottom 42 of the strip 12. Except inthe area of the V-shaped groove 40, the outer surfaces of the retainingportion 32 are adapted to substantially conform to the inner surfaces ofthe groove 22. Thus, the cross-sectional area of the retaining portion32, that is, the area bounded by the legs 38, is less than thecrosssectional area of the dovetail groove 22, that is, the area boundedby the walls 26, bottom 2S, and opening 24. In this manner, whenpressure is applied to the top surface 44 of the operating portion 30,the legs 38 are distorted or forced outwardly and downwardly, therebymoving against the bottom 28 and Walls 26 of the groove 22,

perspective View of the whereby frictional engagement between the strip12 and the groove 22 is provided.

Although the particular construction shown in the drawings is preferred,other forms of the groove 22 and retaining portion 32 may be provided;for exarnpe, these cooperating elements may be of other shapes, providedthat the inlet 24 be constricted to provide for retention of the strip12. Also, in order to reduce the cross-sectional area of the retainingportion 32, an opening may pass through the portion 32, rather thanproviding a V-shaped groove 40 therein.

Sin-ce the strip 12 is to be distortable, the strip 12 is constructed ofan elastic material, such as rubber or plastic. Also, since the strip isfrictionally retained in the groove 22, it is preferred that thematerial used have a relatively high co-eicient of friction.Advantageously, the elastic strip 12 is made of an extrudable ormoldable elastomeric material. It is preferred that polyurethane be usedsince this material is not subject to the same deteriorating effects asrubber. Desirably, the elastic strip 12 has a durometer ranging fromabout l to 98, but preferably, the range is from about 55 to 80.

Referring to FIGURE 3, a scoring element S is shown in operatingassociation with an elastic strip 12 and the operating head 10, aportion of corrugated cardboard C being shown therebetween. As thescoring element S applies pressure to the corrugation C, pressure istransferred to the elastic strip 12 and the legs 38 of the strip 12 arecaused to diverge away from each other. Thus, the outer surfaces of thelegs 38 are forced into frictional engagement with the walls 26 of thegroove 12, and substantially prevent slippage of the strip l12 withinthe groove 22.

It is thus seen that the above-described invention accomplishes all ofthe foregoing objects. First, the elastic strip 12 is readily and easilyinserted into the groove 22 provided on the machine element or roller10. Merely by inward compression of the retaining portion 32, insertionof the retaining portion 32 into the groove 22 is possible. Thus, by asimple manual operation, the strip 12 may be connected to the head 10.Using this construction, therefore, an entire strip 12, or portionthereof, may be replaced simply by pulling the Iretaining portion 32 outof the groove 22, thereby avoiding the necessity of dismantling theentire machine and sending the head back to the manufacturer for repairWork. Rather than having several hours or several days of down time fora machine, it is possible to make the necessary repairs in a matter ofminutes. Furthermore, when pressure is applied to the strip 12, theunique construction of the strip 12 allows distortion of the legs 38 forfrictional gripping of the walls 26 of the groove 22. Thus, it isunnecessary to secure the strip 12 to the operating head 10 by cement orglue.

In summary, applicants invention provides an easily removable andinsertable elastic strip, which is adaptable to be firmly maintained onan operating element without the use of an adhesive.

While in the foregoing -there has been a detailed description of aparticular embodiment of the pres-ent invention, it is to be understoodthat all equivalents obvious to those having skill of the art to beincluded within the scope of the invention, as claimed.

What I claim and desire to secure by Letters Patent is:

1. In combination, a substantially cylindrical operating machine memberhaving a groove circumferentially formed in its outer periphery and withside and bottom surfaces, said groove having a restricted opening, andan integral strip of substantially incompressible elastic materialhaving a working portion and a retaining portion, said retaining portionhaving leg portions which are received in said groove, said retainingportion having a cross-sectional area slightly less than thecross-sectional area of said groove, the total thickness of the legstaken in a direction parallel to the surface of the machine member andperpendicular to the axis of the groove being substantially thethickness of the restricted opening of the groove, and the side portionsof the said `retaining portion conforming to the inner surface of boththe sides and bottom of said groove whereby upon inward compression ofsaid legs, said I retaining portion may be inserted into said groove andafter said retaining portion is in said groove, downward pressureagainst said working portion causes said legs to diverge outwardlyagainst the surface of said sides and bottom of said groove forfrictional retention of said strip with said groove.

2. The combination of claim 1 wherein said groove is a dovetail groove,and said integral strip is an elastomeric material having a coeflicientof friction sufficient to prevent slipping of said strip within saidgroove as downward pressure is applied to said strip.

3. The combination of claim 1 wherein said strip is made of polyurethaneand said legs are diverging.

4. The combination of claim 1 wherein the durometer of said strip rangesfrom about to 80.

References Cited UNITED STATES PATENTS 332,998 12/1885 Coupland 29-129 X333,072 12/1885 House et al 152-323 X 1,095,861 5/1914 Henderson 152-329X 1,194,177 8/1916 Henderson 152-329 X 2,631,871 3/1953 Stone 285-3382,971,565 2/1961 Jarund 156-580 3,133,340 5/1964 Pinelli 29-l29.5

FOREIGN PATENTS 380,364 9/ 1959 Switzerland.

LOUIS O. MAASSEL, Primary Examiner.

1. IN COMBINATION, A SUBSTANTIALLY CYLINDRICAL OPERATING MACHINE MEMBERHAVING A GROOVE CIRCUMFERENTIALLY FORMED IN ITS OUTER PERIPHERY AND WITHSIDE AND BOTTOM SURFACES, SAID GROOVE HAVING A RESTRICTED OPENING, ANDAN INTEGRAL STRIP OF SUBSTANTIALLY INCOMPRESSIBLE ELASTIC MATERIALHAVING A WORKING PORTION AND A RETAINING PORTION, SAID RETAINING PORTIONHAVING LEG PORTION WHICH ARE RECEIVED IN SAID GROOVE, SAID RETAININGPORTION HAVING A CROSS-SECTIONAL AREA SLIGHTLY LESS THAN THECROSS-SECTIONAL AREA OF SAID GROOVE, THE TOTAL THICKNESS OF THE LEGSTAKEN IN A DIRECTION PARALLEL TO THE SURFACE OF THE MACHINE MEMBER ANDPERPENDICULAR TO THE AXIS OF THE GROOVE BEING SUBSTANTIALLY THETHICKNESS OF THE RESTRICTED OPENING OF THE GROOVE, AND THE